The Darwin family's first DUO model — two domain-verified SOTA models served as a single OpenAI-compatible endpoint.
🏆 GPQA Diamond (full 198 questions): 88.38%
Darwin-28B-REASON single 69.70 % · AWAXIS-Think-31B single 77.27 % · first cascade 83.84 % · Darwin-DELPHI DUO 88.38 %
Darwin-60B-DUO unifies two specialist models from the Darwin family behind a single API:
Darwin-28B-REASON — Hugging Face leaderboard GPQA Diamond rank #3, English graduate-level reasoning specialist.
AWAXIS-Think-31B — National K-AI Leaderboard rank #1 (operated by the Ministry of Science and ICT of the Republic of Korea), Korean specialist.
A Hybrid-A router automatically dispatches each request to the optimal strategy (single route / sequential collaboration / ensemble), so callers see one model and one endpoint while internally benefiting from both specialists.
Model Description
Darwin-60B-DUO is a gateway-orchestrated aggregate of two constituent base models. The repository contains a FastAPI orchestrator, configuration, and Docker Compose recipe. The model weights themselves live in the constituent repositories and are loaded at runtime by two vLLM backends.
Note on AWAXIS membership. AWAXIS-Think-31B is also part of the Darwin family — it is the Korean specialist branch distilled by the Darwin team on top of Google's Gemma-4 base, complementing the original Qwen3.5-line Darwin lineage as the family's second axis.
Hybrid-A Orchestration
The gateway analyzes each incoming request and selects one of five strategies. The default distribution observed on representative traffic is:
Strategy
When it fires
Backends called
Cost vs. single 30 B
Share
route_awaxis
Korean-dominant input
AWAXIS only
1×
~50 %
route_darwin
English-dominant input
Darwin only
1×
~20 %
split_refine
Korean output requiring rigorous English / STEM reasoning
Darwin (draft) → AWAXIS (polish)
2×
~15 %
split_refine_reverse
English output requiring Korean cultural / linguistic context
AWAXIS (draft) → Darwin (polish)
2×
~5 %
ensemble_v1
Short-answer / multiple-choice queries
Both backends with self-consistency + cross-verification tournament
2×
~10 %
Average effective cost is approximately 1.3× a single 30 B model — 70 % of traffic is served by a single backend; the remaining 30 % uses both.
Intended Use
Primary use cases
Bilingual Korean-English assistants that require both Korean fluency and high-quality English reasoning.
Single-endpoint integration where downstream tooling already targets the OpenAI Chat Completions API (LangChain, LlamaIndex, OpenAI SDK, Continue, Cursor, etc.).
Cost-conscious deployment — most traffic is served by a single backend at 1× cost while difficult cross-domain queries automatically receive a 2× collaboration.
Out-of-scope
Vision / video generation. Both constituent models are text-mode only as deployed here (--limit-mm-per-prompt {"image":0,"video":0}).
Real-time streaming. Initial gateway release does not stream token-by-token. Streaming is planned for v1.1.
Direct AutoModel.from_pretrained() loading. This repository contains an orchestrator, not unified weights. Use the gateway or Docker Compose.
1git clone https://huggingface.co/FINAL-Bench/Darwin-60B-DUO
2cd Darwin-60B-DUO
34# HF token is needed only to download constituent weights on first launch5exportHF_TOKEN=hf_xxx
6docker compose -f docker/docker-compose.yml up -d
78# Verify9curl http://localhost:8000/v1/models
10# {"object":"list","data":[{"id":"darwin-60b-duo",...}]}
No external HF download. Both weights are inside this repo (./darwin-28r, ./awaxis-31b), so vLLM serves directly from local LFS without re-downloading from upstream repos.
Single-GPU collocation. With FP8 quantization the combined footprint is ~30 GB. Set both backends to CUDA_VISIBLE_DEVICES=0 and --gpu-memory-utilization 0.45 to colocate on a single 80 GB B200 / H100.
OpenAI-compatible call
python
1from openai import OpenAI
23client = OpenAI(base_url="http://localhost:8000/v1", api_key="anything")45# The router picks split_refine (Korean output with English/STEM reasoning)6resp = client.chat.completions.create(7 model="darwin-60b-duo",8 messages=[{9"role":"user",10"content":"Explain the practical difference between GPT-5 and Claude's reasoning, in Korean.",11}],12)13print(resp.choices[0].message.content)14# Darwin produces the English reasoning; AWAXIS polishes it into natural Korean.
You can also force a specific strategy via the non-standard duo_strategy field:
python
1resp = client.chat.completions.create(2 model="darwin-60b-duo",3 messages=[{"role":"user","content":"Which is correct? (A) ... (B) ..."}],4 extra_body={"duo_strategy":"ensemble_v1"},# force MAJ@8 + cross-verify5)
Inspect the chosen strategy in the response under _duo_route:
🛠️ Build Your Own DUO (the gateway is model-agnostic)
The gateway/ in this repo is not specific to Darwin and AWAXIS — it is a general, Apache-2.0 orchestrator that fuses any two OpenAI-compatible backends into a single endpoint. We're open-sourcing it because the pattern is broadly useful, and we'd love to see what the community builds.
The core idea in one sentence
Two small specialists, automatically routed, beat one big generalist on cost and quality — and the user only ever sees a single model.
Pair anything
You don't need our models. Point the gateway at your favourite two and you have a DUO in minutes:
Pair
Why it works
reasoning model + multilingual model
rigorous logic, fluent output (what we did)
fast small model + slow accurate model
cheap on easy queries, escalate only hard ones
code model + general chat model
route by "is this code?"
English specialist + your-language specialist
localize without losing reasoning depth
Adapt in 2 steps
bash
1# Step 1 — point at your two backends (any vLLM / TGI / OpenAI-compatible server)2python gateway/server.py --port 8000\3 --darwin-url http://your-model-A:8000/v1 \4 --awaxis-url http://your-model-B:8000/v1
python
1# Step 2 — teach the router when to use which model (gateway/router.py)2defselect_strategy(text):3if is_code(text):return"route_model_a"# send code to the code model4if is_korean(text):return"route_model_b"# send Korean to the KO model5if is_mcq(text):return"ensemble_v1"# short-answer → both + pick6if needs_polish(text):return"split_refine"# draft with A, polish with B7return"route_model_b"# sensible default
That's it. The gateway handles the OpenAI API surface, parallel calls, response merging, and _duo_route transparency for you.
What's included vs. what's proprietary
✅ Open (Apache-2.0): the gateway — router, single-route, sequential-refine, and a baseline ensemble. Enough to build a fully working DUO of your own.
🔒 Proprietary (Darwin-DELPHI): the test-time engine and prompt recipes that push this DUO to 88.38 % on GPQA Diamond (above the naive oracle ceiling). The open gateway gives you the architecture; the leaderboard score is ours.
Extend it
DUO → TRIO → N-way: add a third backend and a third route; the merge logic generalizes.
Smarter routing: swap the keyword heuristics in router.py for a tiny learned classifier.
New strategies: contribute your own (debate, best-of-N, tool-use) via PR.
Fork it, point it at your models, and tell us what you built. Open a discussion on the Community tab — good routing recipes and new backend pairings are exactly the kind of thing we want to feature.
Darwin Family
Darwin-60B-DUO sits at the confluence of two complete lineages — the Qwen3.5-based Darwin lineage (English reasoning) and the Gemma-4-based Darwin Korean-specialist branch (AWAXIS). The full family tree, with both constituent ancestries fully expanded:
mermaid
1graph TD
2%% Lineage A — English reasoning3 A1[Cohere Command A+ - 218B foundation]:::found --> A2[Darwin-28B-Opus - English reasoning base]:::parent
4 A2 --> A3[Darwin-28B-REASON - HF GPQA Diamond #3]:::spec
56%% Other Darwin parents7 A1 -.-> P1[Darwin-218B-Delphi - cascade flagship GPQA 90.91%]:::parent
8 A2 -.-> P2[Darwin-9B - omni-modal ko/en compact]:::parent
9 P2 -.-> P3[Darwin-31B-Opus - Korean multimodal base]:::parent
1011%% Lineage B — Korean specialist12 B1[Google Gemma-4-31B-it - Korean/multilingual base]:::found --> B2[TeichAI gemma-4-31B-it-Claude-Opus-Distill-v2]:::parent
13 B2 --> B3[AWAXIS-Think-31B - National K-AI Leaderboard #1, Darwin family Korean specialist]:::spec
1415%% The DUO unification16 A3 --> DUO[Darwin-60B-DUO - this model]:::duo
17 B3 --> DUO
1819classDef found fill:#e8f0fe,stroke:#1a73e8,color:#0a0a0a20classDef parent fill:#fff4e5,stroke:#f29900,color:#0a0a0a21classDef spec fill:#e6f4ea,stroke:#34a853,color:#0a0a0a22classDef duo fill:#fce8f3,stroke:#d81b60,color:#0a0a0a,stroke-width:3px
Plain-text fallback
Darwin Family
Lineage A — English reasoning (Qwen3.5-line)
└── Cohere Command A+ (218B foundation)
└── Darwin-28B-Opus (English reasoning base)
└── Darwin-28B-REASON 🥉 ← HF GPQA Diamond #3
(English reasoning specialist)
│
│ Related Darwin parents in this lineage:
│ • Darwin-218B-Delphi (cascade flagship, GPQA Diamond 90.91 %)
│ • Darwin-9B (omni-modal ko/en compact)
│ • Darwin-31B-Opus (Korean multimodal base)
Lineage B — Korean specialist (Gemma-4-line)
└── Google Gemma-4-31B-it (Korean / multilingual base)
└── TeichAI gemma-4-31B-it-Claude-Opus-Distill-v2
└── AWAXIS-Think-31B 🥇 ← National K-AI Leaderboard #1
(Darwin family Korean specialist)
│ │
└──────── DUO unification ────┘
↓
⭐ Darwin-60B-DUO ⭐ ← THIS MODEL
"Two SOTAs, one OpenAI-compatible endpoint."
The HF Model tree widget (right sidebar) automatically renders the upstream chain from each base_model declared in the YAML frontmatter, so the full ancestry — Cohere Command A+ and Google Gemma-4-31B-it at the roots — is browsable directly on this page.
Operation Modes
Mode 1 — Route (single backend, ~70 % of traffic)
The router selects one backend based on language ratio and lightweight keyword heuristics:
korean_ratio(prompt) > 0.3 → AWAXIS
ASCII / code / math markers (def , import, \boxed, prove, …) → Darwin
One model drafts, the other polishes. The polish instruction is language-adaptive:
User: "Explain entropy intuitively in Korean."
Step 1 — Darwin (rigorous English reasoning)
"Entropy quantifies the number of microstates compatible
with a given macrostate, representing disorder ..."
Step 2 — AWAXIS (natural Korean polish)
"엔트로피는 쉽게 말하면 '무질서함의 정도'입니다.
같은 모습으로 보이지만 사실 그 안에 ..."
The reverse path (AWAXIS draft → Darwin polish) fires when the output language is English but the prompt requires Korean cultural or linguistic context.
Mode 3 — Ensemble V₁ Tournament (~10 % of traffic)
For multiple-choice and short-answer queries, both backends produce N = 8 samples at temperature 0.7. Each backend's answer is its own majority vote (self-consistency). If the two majorities agree → return. If they disagree → each backend verifies the pair (cross-verification), and the tournament winner is selected. A confidence tiebreaker (own-vote count) resolves split verdicts.
Self-contained: all model weights (both constituents) are included in this repository — git clone once and you have everything. Total LFS payload: ~120GB.
Evaluation
Verified constituent scores
Constituent
Benchmark
Rank
Darwin-28B-REASON
Hugging Face GPQA Diamond
#3
AWAXIS-Think-31B
National K-AI Leaderboard (Republic of Korea, MSIT)
#1
Darwin-60B-DUO aggregate
Benchmark
Status
GPQA Diamond (full 198 questions)
88.38% (175/198) — see benchmarks/
KMMLU
TBA
CLIcK (Korean cultural reasoning)
TBA
Helmet / Ruler (long context)
TBA
Needle-in-Haystack 32 K / 128 K
NIAH 32 K: 5/5 per backend (sanity, single model only) — full DUO numbers TBA
Aggregate DUO benchmark results will be published in benchmarks/ after formal evaluation. The verified constituent ranks above are independent third-party measurements and are not aggregate DUO scores.
Cost / latency notes
Route mode: comparable to a single 30 B FP8 backend (1× latency, 1× compute).
Ensemble V₁: ~2× compute (parallel) plus a short cross-verify round when majorities disagree.
Bias, Risks, and Limitations
Hallucination. Standard LLM caveats apply. Both backends can produce confident but incorrect outputs, especially on out-of-distribution queries.
Disagreement bias. Empirically, the V₁ tournament occasionally selects a wrong answer that both backends collectively favor over a single backend's correct one. The gateway exposes the routing decision in _duo_route for auditability.
Language coverage. Best performance on English and Korean. Other languages fall back to the closer-fit backend without explicit optimization.
Combined weights are not bundled. The aggregator pulls each backend's weights from the constituent repositories. Network and disk for both is required.
Two-GPU baseline. BF16 deployment requires two GPUs. FP8 quantization enables single-GPU operation on B200 / H100 (80 GB).
Training data cut-off. Darwin-28B-REASON: ~ 2026-Q1. AWAXIS-Think-31B: ~ 2026-Q1.
License
Darwin-60B-DUO inherits the Gemma Terms of Use as its effective combined license — the more restrictive of the two constituent licenses.
Constituent
License
Darwin-28B-REASON
Apache-2.0
AWAXIS-Think-31B
Gemma (inherited from Gemma-4)
Darwin-60B-DUO (aggregate)
Gemma (combined-license inheritance)
The orchestrator code (gateway/, docker/) is offered under Apache-2.0 to maximize developer flexibility; combined-license inheritance applies to served model behavior only.
Issues and discussions: please open a thread on the Community tab of this repository.
Citation
bibtex
1@misc{darwin60b-duo-2026,
2 title = {Darwin-60B-DUO: A single-endpoint DUO of an English-reasoning SOTA
3 and a Korean SOTA via Hybrid-A orchestration},
4 author = {FINAL-Bench Team and Anserwise Team and VIDRAFT},
5 year = {2026},
6 howpublished = {Hugging Face},
7 url = {https://huggingface.co/FINAL-Bench/Darwin-60B-DUO}
8}